1. Field of the Invention
The present invention relates generally to ferrule holders and associated fiber optic connectors used in optical communications networks, optical devices, and the like to optically couple optical fibers. More specifically, the present invention relates to a ferrule holder and an associated fiber optic connector having improved anti-withdrawal and anti-rotation features, such as a twin-threaded configuration, a single-threaded configuration, a splined configuration, a broached configuration, a counter-bored configuration, a dented configuration, a finned configuration, etc. These anti-withdrawal and anti-rotation features assist in holding an optical fiber in secure optical and/or physical contact with a ferrule within the ferrule holder and associated fiber optic connector.
2. Technical Background of the Invention
A conventional fiber optic connector includes, among other parts, an outer housing, an alignment sleeve, an inner structure that is configured to retain an optical fiber cable, a heat shrink and/or boot that is/are configured to retain and protect the optical fiber cable, and a ferrule holder that is configured to hold a ferrule. This ferrule is in optical and/or physical contact with an optical fiber that typically enters the ferrule holder opposite the ferrule. In operation, the fiber optic connector is mated with another fiber optic connector, such as a plug with a receptacle, for example, bringing the corresponding ferrules into optical and/or physical contact. This, of course, brings the corresponding optical fibers into optical contact, thereby creating an optical connection. The ferrules may be single or multi-fiber ferrules. The ferrule holders holding these ferrules may assume a variety of shapes, but are typically substantially cylindrical, and are manufactured from a metallic material or plastic material, due to the fact that such materials are relatively easy to machine or cast.
The optical fiber that enters the ferrule holder opposite the ferrule is typically secured in the ferrule holder and to the ferrule using an adhesive, preventing withdrawal and rotation of the optical fiber in relation to the ferrule holder and the ferrule. One major problem that the fiber optic industry currently struggles with, however, is that of delamination of the adhesive, caused by the poor bonding that exists between an optical fiber and a metallic material ferrule holder, for example. In addition, the adhesive used is prone to shrinking and detaching from the underlying substrate.
A variety of techniques have been developed to deal with the problems described above, including the use of various mechanical anchoring mechanisms and adhesive compositions. None of these techniques, however, provide adequate anti-withdrawal and anti-rotation characteristics. The techniques fail existing pull and twist tests in the face of the delamination and shrinkage problems described above. Thus, what is still needed in the art is a ferrule holder and associated fiber optic connector having improved anti-withdrawal and anti-rotation features.